Cancer scan could remove need for radiotherapy in cured patients

The late effects of radiotherapy in patients with early stage Hodgkin lymphoma could be reduced by using a scan to determine those who actually need it, according to a study published in the New England Journal of Medicine (2015; doi:10.1056/NEJMoa1408648).

The trial demonstrated that a positron-emission tomography (PET) scan immediately after treatment with chemotherapy can identify patients who have a very good outcome without additional radiotherapy. The trial was conducted by the United Kingdom Cancer Research Institute and led by scientists from The University of Manchester and the Christie NHS Foundation Trust in the United Kingdom.

Hodgkin lymphoma is a cancer that develops in the lymphatic system, which is a network of vessels and glands spread throughout the body. The current standard treatment is for all Hodgkin lymphoma patients to receive chemotherapy, followed by radiotherapy. However, this radiotherapy comes with undesirable late effects, such as cardiovascular disease and other cancers. These occur despite the fact that patients have already been cured of Hodgkin lymphoma.

The 602 patients who agreed to take part in the RAPID trial had a PET scan performed after their chemotherapy. Patients with positive results received radiotherapy. Those with negative results were divided into two groups, and one group (211 patients) received no further treatment, while the other group (209 patients) had the standard radiotherapy.

After 3 years of regular check-ups, the proportion of patients who were alive and free of disease was 94.6% in the radiotherapy group, and 90.8% in the group that had not received further treatment.

"This research is an important step forward. The results of RAPID show that in early stage Hodgkin lymphoma radiotherapy after initial chemotherapy marginally reduces the recurrence rate, but this is bought at the expense of exposing to radiation all patients with negative PET findings, most of whom are already cured," said the lead researcher, Professor John Radford, MD, who is based at The University of Manchester's Institute of Cancer Sciences and the Christie NHS Foundation Trust.

Despite the findings from this study the researchers stress that a longer follow-up period is needed in order to determine whether this approach will ultimately lead to fewer late side-effects and improved overall survival.

"This groundbreaking clinical trial shows that, by using scans to predict an individual's risk of relapse, many patients can remain disease-free with just chemotherapy alone,” said Matt Kaiser, Head of Research at Leukaemia & Lymphoma Research, which is the charity that funded the study. “Radiotherapy can cause a range of long-term problems like heart disease and hard-to-treat second cancers. As many Hodgkin lymphoma patients are relatively young, it is particularly important to avoid using intensive treatment when it is unnecessary."